24 research outputs found

    A Prototype of Co-Frequency Co-Time Full Duplex Networking

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    Radio FD has emerged as an attractive technique capable of doubling the spectral efficiency over half duplex. However, for signal reception, an FD node needs to suppress its transmitter's signals quite significantly. In point to point communication systems, these transmitter signals are termed self-interference. When working with an FD mobile network, the self-interference problem becomes much more complicated because the receiver of an FD base station (BS) receives interference not only from its BS transmitter in its cell, but also from those in the surrounding cells. For the UL channel, self-interference extends to the problem of multiple interference. And, a similar interference problem can be found among the MSs over a DL channel. In both cases, the interference owing to the FD implementation spreads beyond the scope of the self-interference. This article describes the development of FD BSs that use antenna arrays to deal with the BSs' interference, and thus enable FD communication over the UL channel, where the theoretical focus is placed on how to use the antenna array to nullify the multiple interference and receive the signals of the desired MSs simultaneously. To complete the system construction, FD MSs have also been developed to enable DL transmission. A prototype system is described for the scenario of two cells and one FD MS for tests of FD communication over UL channels and DL channels in terms of video performance. Good video quality is demonstrated at both the BS and MS

    Design and research of moving objects dimension measurement system based on linear array CCD

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    <p> A novel moving objects dimension measurement system based on the linear array CCD is designed. The light source is a pulsed laser with pulse width 200ns. Single point of light passes through lens converted to parallel light which will illuminate to the CCD through the moving object to be tested. CCD pixels which are blocked by the object while light is on are low, and the remaining pixels are high conversely. The distance of the tested objects while light is on can be ignored since the light pulse width is much smaller than the integration time of CCD (generally). The size of the tested object can be achieved by the number of dark pixels of CCD while light is on. This paper introduces the principle and composition of the dimension measurement system. The results show that this system can measure the size of moving objects and measuring accuracy is better than 50 microns. Accuracy and stability of the system can achieve actual production requirements when the object&#39;s moving speed is smaller than 50mm/s. Optimizing the parallelism of the parallel light, the measurement accuracy can be further improved. &copy; 2016 SPIE.</p

    Bisphenol AF Promoted the Growth of Uterus and Activated Estrogen Signaling Related Targets in Various Tissues of Nude Mice with SK-BR-3 Xenograft Tumor

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    Environmental estrogens can promote the growth, migration, and invasion of breast cancer. However, few studies evaluate adverse health impacts of environmental estrogens on other organs of breast cancer patients. Therefore, the present study investigated the effects of environmental estrogen bisphenol AF (BPAF) on the main organs of female Balb/cA nude mice with SK-BR-3 xenograft tumor by detecting the organ development and gene expression of targets associated with G protein-coupled estrogen receptor 1 (GPER1)-mediated phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinase (MAPK) signaling pathways in hypothalamus, ovary, uterus, liver, and kidney. The results showed that BPAF at 20 mg/kg bw/day markedly increased the uterine weight and the uterine coefficient of nude mice compared to SK-BR-3 bearing tumor control, indicating that BPAF promoted the growth of uterus due to its estrogenic activity. Additionally, BPAF significantly up-regulated the mRNA relative expression of most targets related to nuclear estrogen receptor alpha (ER&alpha;) and GPER1-mediated signaling pathways in the hypothalamus, followed by the ovary and uterus, and the least in the liver and kidney, indicating that BPAF activated different estrogen activity related targets in different tissues. In addition, BPAF markedly up-regulated the mRNA expression of GPER1 in all tested tissues, and the molecular docking showed that BPAF could dock into GPER1. Because gene change is an early event of toxicity response, these findings suggested that BPAF might aggravate the condition of breast cancer patients through exerting its estrogenic activity via the GPER1 pathway in various organs

    The Interaction Test of Binary Mixtures of Endocrine-Disrupting Chemicals Using In Vitro Bioassays

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    Typical environmental endocrine-disrupting chemicals (EDCs) such as estradiol valerate (EV), diethylstilbestrol (DES), di-2-ethylhexyl phthalate (DEHP), mono-2-ethylhexyl phthalate (MEHP), and bisphenol A (BPA) have a strong reproductive and developmental toxicity at low concentrations. However, information on their joint toxicity is scarce. In this study, we evaluated the combined effects of EV and other four EDCs (DES, DEHP, MEHP, and BPA) on the human breast MCF-7 cells by detecting the cell proliferation, intracellular reactive oxygen species (ROS) levels, and estrogen receptor alpha (ERĪ±) protein expression using equal concentration ratio method. The results showed that, after exposure for 24, 48, and 72ā€‰h, single EV, DES, and BPA can promote the proliferation of MCF-7 human breast cancer cells, and EV has the strongest effect in inducing cell proliferation. DEHP and MEHP cannot induce MCF-7 cell proliferation for all exposure time, while cell proliferation induced by EV was significantly attenuated by DES, BPA, DEHP, and MEHP when they mixed with EV. For intracellular ROS, single EV, BPA, DES, DEHP, and MEHP elevated intracellular ROS levels for different exposure time. Similar to the cell proliferation, DES and BPA decreased intracellular ROS levels induced by EV when they mixed with EV for 24ā€‰h. EV, DES, and BPA exposed alone or combined with EV upregulated the ERĪ± protein expression. However, DEHP and MEHP exposed alone or combined with EV had no effect on ERĪ± protein expression, indicating that DEHP or MEHP could attenuate ERĪ± protein expression upregulated by EV. These results showed that the joint toxicity of binary mixtures of EV and other EDCs do not interact in a synergistic fashion in inducing cell proliferation, intracellular ROS levels, and ERĪ± protein expression. These findings have important implications in the human risk assessments of EV mixed with other EDCs in the environment

    Fabrication of high-stability Ni-PSF@PAO40 microcapsules and their lubricating properties in polyamide 6

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    Novel Ni-PSF@PAO40 microcapsules (NPPMS) with high stability were prepared by using a combined processing method of electroless nickel plating and solvent volatilization. The results indicate that Ni is completely assembled on the surfaces of PSF/PAO40 microcapsules with the encapsulation capacity of NPPMS achieved at 50%. Organic solvents immersion shows that NPPMS have an excellent chemical stability. Macro thermal stability tests reveal that the softening temperature of NPPMS is increased up to over 400 Ā°C while it becomes lower than 200 Ā°C for PSF/PAO40 microcapsules. Furthermore, NPPMS were embedded into polyamide 6 (PA6) to prepare PA6/NPPMS composites. The cross-sectional morphology shows that NPPMS are intact in PA6 matrices. The microhardness of PA6 is effectively improved with the incorporation of NPPMS. As compared with neat PA6, the coefficient of friction (COF) for PA6/NPPMS composites with 10% NPPMS could be reduced by 87.7% (from 0.49 to 0.06) and the wear rate could be decreased by 96.8% (from 1.29Ɨ10āˆ’āµ to 4.15Ɨ10āˆ’ā· mmĀ³/(NĀ·m)). Further studies confirmed that increasing test loads and test temperatures was beneficial to improve the lubrication performance of NPPMS despite the opposite trend occurred when increasing the sliding speeds. It has been demonstrated that synergistic effects between PAO40 and Ni layer play an important role in improving the tribological properties of PA6. Therefore, NPPMS significantly improve the ability of microcapsules to resist a harsh environment, which has important scientific significance for expanding the use of microcapsules more practically in self-lubricating composites

    In Vitro Profiling of Toxicity Effects of Different Environmental Factors on Skin Cells

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    The skin is constantly exposed to a variety of environmental threats. Therefore, the influence of environmental factors on skin damage has always been a matter of concern. This study aimed to investigate the cytotoxic effects of different environmental factors, including cooking oil fumes (COFs), haze (PM2.5), and cigarette smoke (CS), on epidermal HaCaT cells and dermal fibroblast (FB) cells. Cell viability, intracellular reactive oxygen species (ROS) generation, inflammatory cytokine levels, and collagen mRNA expression were used as toxicity endpoints. Additionally, the effects of ozone (O3) on cell viability and release of inflammatory cytokines in 3D epidermal cells were also examined. The results showed that the organic extracts of CS, COFs, and PM2.5 significantly inhibited the viability of HaCaT and FB cells at higher exposure concentrations. These extracts also increased intracellular ROS levels in FB cells. Furthermore, they significantly promoted the release of inflammatory cytokines, such as IL-1Ī± and TNF-Ī±, in HaCaT cells and down-regulated the mRNA expression of collagen I, III, IV, and VII in FB cells. Comparatively, SC organic extracts exhibited stronger cytotoxicity to skin cells compared to PM2.5 and COFs. Additionally, O3 at all test concentrations significantly inhibited the viability of 3D epidermal cells in a concentration-dependent manner and markedly increased the levels of TNF-Ī± and IL-1Ī± in 3D epidermal cells. These findings emphasize the potential cytotoxicity of COFs, PM2.5, CS, and O3 to skin cells, which may lead to skin damage; therefore, we should pay attention to these environmental factors and take appropriate measures to protect the skin from their harmful effects
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